Install libpq5 by entering the following commands in the terminal:
sudo apt update sudo apt install libpq5
PostgreSQL C client library
libpq is a C library that enables user programs to communicate with the PostgreSQL database server. The server can be on another machine and accessed through TCP/IP. This version of libpq is compatible with servers from PostgreSQL 8.2 or later. . This package contains the run-time library, needed by packages using libpq. . PostgreSQL is an object-relational SQL database management system.